VARIACIONES MORFOMÉTRICAS DE Ophiocoma aethiops Lütken, 1859 EN TRES ZONAS DE LA ISLA GORGONA

Abstract

Ophiuroids are common rocky shore inhabitants; however, little is known about the population structure of most species. This work aims at presenting detailed information on morphometric relations of Ophiocoma aethiopsin Gorgona National Natural Park, Colombian Pacifi c. For this purpose,  300  individuals  collected  at  three  different  locations  of  the  island  were  weighed,  and the longest arm and disk diameter measured. The weight ranged between 0.1 and 47 g, with most being under 15 g; the longest arm length ranged from 15.39 to 163.64 mm, with most between 60 and 140 mm. Disk diameter ranged from 3.56 to 37.6 mm, with most between 15 and 30 mm. A positive linear relation was observed between disk diameter and arm length. The relations between weight and disk diameter and between weight and arm length were both exponential, suggesting that body size increases rapidly in juveniles with a posterior mass gain. Morphometric differences did not allow concluding that the individuals from different locations were separate populations. Finally, considering that there is a high proportion of juveniles, the population of this species is in equilibrium, at least during the time of sampling.